Water jet propulsion apparatus



May 27, 1969 F. L. THORNBURG ET AL 3,446,177

WATER JET PROPULSION APPARATUS P Sheet Filed April 18, 1968 INVI'INI'ORS THORNBURG FRANCIS L GEORGE E. TURNLEY, JR.

gen s y 1969 F. L. THORNBURG ET AL 3,446,177

WATER JET PROPULSION APPARATUS Sheet Filed April 18, 1968 v ol llllllllllllllllllll In q r vf win 5 1 i m m R 5 m 8 INVIEN'IORS FRANCIS L. THORNBURG GEORGE E. TURNLEY, JR.

Agen fs United States Patent 3,446,177 WATER JET PROPULSION APPARATUS Francis L. Thornburg, Canoga Park, and George E.

Turnley, Jr., Los Angeles, Calif., assignors to Lockheed Aircraft Corporation, Burbank, Calif.

Filed Apr. 18, 1968, Ser. No. 722,253 Int. Cl. B63h 11/08 U.S. Cl. 115-16 Claims ABSTRACT OF THE DISCLOSURE A water jet propulsion apparatus for a high speed, marine vehicle having an alternate inlet system comprising a primary inlet for operational efficiency in relatively clear water and a secondary inlet for most efficient operation in Weed-infested water. A weed chopping device is located adjacent the secondary inlet to sever any weeds ingested into the apparatus.

Background of the invention and description of the prior art This invention generally relates to water jet propulsion systems, and more particularly to inlet ducting means for providing etficient propulsion operation in all types of water.

An environmental problem in many river and delta areas in the dense aquatic vegetation prevalent in most of the waterways. In many areas the presence of such infestations is aggravated by a tropical climate which promotes a prolific rate of growth of this vegetation. Because of the tremendous popularity of pleasure boating in these areas and also due to the requirements of military operations in many swampy terrain regions, there is an immediate requirement for a marine surface vehicle capable of operating in such river, delta and coastal Waters. Furthermore, this vehicle must not only be able to successfully penetrate the heavy weed concentrations located in these waters; it must also be able to navigate in waters polluted by heavy debris or submerged objects. In addition, this craft must still retain a high speed dash capable of operating in such river, delta and coastal wacurrent military requirements also demand that the noise level of the propulsion system of vehicles of this type be at such a level as to permit clandestine operations.

Heretofore, several marine vehicle concepts have been set forth to meet these requirements. A few of these concepts are:

1) A craft having a conventional hull and driven by a weed-free propeller. This craft has met with a varying degree of success. However, its efiiciency and configuration are not desirable for high speed, high powered propulsion systems. Being of deep draft design, the craft is susceptible to damage when struck by submerged objects. Furthermore, the propeller is still susceptible to weed entanglement in densely weeded waters.

(2) A flat bottomed, low draft boat equipped with a water jet propulsion system. This propulsion system incorporates a rotary weed chopper device at the intake to the water jet ducting system. However, as currently designed, the boat has two undesirable features:

(a) The inlet ducting system, being ported at the bottom of the hull, does not provide a means to separate the weeds from the pumped water; even though the ingested weeds are cut to small sizes, this is not sufiicient to prevent clogging of the impeller and the inlet duct; and

(b) The weed chopper cutting blades, being located adjacent the inlet port at the bottom of the hull, are prone to damage by striking logs or other submerged objects. Also, these concessions made in protecting against 3,446,177 Patented May 27, 1969 weed clogging have precluded high speed capability in clear water.

(3) An air boat, i.e., a craft driven by an air propeller. This device appears desirable because the drive system is completely out of the water. However, overhanging branches in many areas are bothersome. Another great disadvantage is the noise created by propeller tip vortices operating at high tip speeds. This noise level far exceeds that generated by the prime mover. In addition, the air propeller provides poor maneuverability under adverse wind conditions and has the inherent disadvantage of a very high thrust vector.

(4) An air cushion vehicle.-This vehicle has all the basic advantages and disadvantages of the air propelled craft. In addition, it has stiff and flexible skirts that are required to form and maintain the air cushion. Its maneuverability under certain conditions is also poor. Its main disadvantage, however, is that its great complexity results in an excessively high cost.

All of the noted concepts can be utilized under certain environments, yet none are fully responsive to all of the operational requirements mentioned above.

Summary of the invention This invention relates to a water jet propulsion ap paratus comprising a first inlet duct having an inlet port on the bottom planing surface of the vehicle, a second inlet duct having an inlet port transverse to the bottom planing surface of the vehicle, and valve means located between the first and second inlet duct for alternately providing communication of one of the inlet ducts to the propulsion means. Weed chopping means are located on the second inlet to sever any weeds ingested into the pump, thereby fulfilling a primary object of the invention, i.e., providing a vehicle capable of operating in all types of hazardous water conditions.

Another object of the invention is to provide a vehicle that will penetrate weed-infested water while being free from damage by any heavy debris or submerged objects.

A further object of this invention is to provide a vehicle that has a high speed dash capability as well as an efficient cruise speed.

Various other objects and advantages will appear from the following description of one embodiment of the invention.

Brief description of the drawings FIGURE 1 is a bottom view of a high speed marine Vehicle showing the water jet propulsion means;

FIGURE 2 is a cross sectional view of the water jet propulsion means taken along lines 22 of FIG- URE 1;

FIGURE 3 is an end view of the alternate inlet means taken along lines 33 of FIGURE 2;

FIGURE 4 is a sectional view of the weed chopping means taken along lines 44 of FIGURE 3;

FIGURE 5 is a sectional view of the vehicle taken along lines 5-5 of FIGURE 1; and

FIGURE *6 is a sectional view of the vehicle taken along lines 6-6 of FIGURE 1.

Detailed description of the invention In the illustrated embodiment of the invention, FIG- URE 1 shows a portion of the bottom planing surface of a marine vehicle hull, generally indicated as 10. The bottom planing surface includes a forward planing surface 11, a pair of outboard planing surfaces 13 extending rearward therefrom, and a center planing surface 15 also extending rearward from the forward planing surface.

An engine 17 (shown schematically in broken lines), which may be of any desirable configuration, is supportedly mounted in the hull .10.

A pump 19 (shown in broken lines) is also supportedly mounted in the hull directly above the center planing surrface and is connected to the engine 17 by means of drive shaft 21 (also shown in broken lines).

FIGURE 2 shows the water jet propulsion system which includes the pump 19 comprising a substantially bowlshaped housing 23 having a rim portion 25 which includes a circular intake port 26 communicating with the interior of the housing 23. An annular flange 27 is located at the base of the bowl-shaped housing 23 and forms a circular discharge port, also communicating with the interior of the housing 23. A discharge nozzle 29 is located adjacent the pump discharge port. It includes an annular flange 31 which is fixedly connected to the annular flange 27 by bolts 33 or other suitable means.

Located adjacent the pump intake port 26 is a primary inlet duct 35 comprising a substantially cylindrical housing 37 having a flanged end 39 bolted, as by bolts 41, or otherwise fixedly connected to the rim portion 25 of the pump housing 23. The other end 43 of the duct 35 extends to the center planing surface 15 to form a primary inlet port 45. Thus, the primary inlet duct 3-5 provides the pump 19 with a direct flow communication with the water beneath the vehicle.

-A grill 47, comprising a plurality of arms 49 integral with a support bar 51, is connected through the bar 51 to the center planing surface 15 at a position forward of the primary inlet port with the grill arms 49 extending over the primary inlet port 45, usually in a cantilevered relationship. Such a grill is utilized to guard against any submerged objects which could damage the components of the pump.

A secondary inlet duct 53 is also located forward of the pump intake port 26. As shown in FIGURES 2 and 3, the secondary inlet duct 53 comprises a housing 55, with one end 57 including a pair of inlet ports 59. This bifurcated inlet is utilized to minimize the height of the inlet duct 53 while maintaining the prescribed water volume, thereby providing a shallow draft design. The other end of the housing is disposed to terminate on the top side of the primary inlet housing 37 and be integrally connected thereto.

A valve 61 is located on the portion of the upper wall of the primary inlet housing 37 which is also common to the secondary inlet housing 55, thereby providing communication between the primary inlet duct 35 and the secondary inlet duct 53. This valve 61 includes a valve gate 63 pivotally connected to the housing 37 by a hinge means 65. The valve 61, pivoting about the hinge 65, is adapted to be located in two alternative positions: a first position (shown by the solid lines in FIGURE 2) provides the pump intake with a direct communication to the primary inlet port 45, while simultaneously closing the secondary inlet ports 59; and a second position (shown by the broken lines in FIGURE 2) provides the pump intake with communication to the secondary inlet ports 59, while closing the primary inlet port 45.

The valve positioning is controlled by an actuator 67 which includes a piston rod 69 and a cylinder 71. The piston rod 69 is pivotally connected to the valve gate 63 by pin means 73 while the cylinder 71 is pivotally connected to the housing 37 by pin means 75. The actuator 67 is hydraulically actuated via lines 68 in a conventional manner.

Located at the mouth of each of the inlet ports 59 is a weed cutting device or weed chopper 77 which is peripherally enclosed by a pair of cylindrical housing members 79 and 81. The housing member 79 has a flanged portion 83 integrally connected to the one end 57 of the housing 55, while the housing member 81 has a flanged portion '85 which is connected to a mating flanged portion 87 of the housing member 79 by bolt means 89. The other end of the housing member 81 includes a circular port 91. An annular ring 93 is located within each of the interiors of the housing members 79 and 81 and is rotatably supported therein by a pair of annular bearings 95. Fixedly mounted within the annular ring 93 are a plurality of cutter blades 97.

FIGURE 4 shows a stator blade 99 integrally connected to a ring 101 which, in turn, is fixedly mounted within the inlet port 59 adjacent the cutter blades 97. The stator blade 99 is located rearwardly of the rotating cutter blades 97. In this arrangement, the cutter blades 97 and the stator blade 99 cooperate to shear any weeds entering the inlet. This action of shearing the weeds against the stator blade 99 prevents any weeds from clinging to the stator blade 99.

Each of the annular rings 93 also includes on its outer periphery an external annular gear 103 extending to a position between the roller bearings 95. FIGURES 2 and 3 show a pinion gear 105, keyed to a shaft 107, which drivingly engages both of the annular gears 103. The shaft 107 is rotatably supported in the housing 79 by a pair of bearings 109. One end of the shaft 107 is externally splined to mate with an internal spline of the shaft 21, which leads to the engine 17, while the other end is externally splined to engage an internal spline of a shaft 111. The shaft 111 extends through a cylindrical shaft support 113, located on the housing 37, and into the pump housing 23, via the pump intake port 36, to support and rotationally drive a pump impeller 20 mounted upon its opposite end. A plurality of sealing glands 115 are located along the shaft 111 to prevent motive fluid from entering the interior of the hull and are secured in place by an end cap and spacer sleeve 117. The end cap 117, in turn, bears against a thrust bearing 119 located on the housing 55. The thrust bearing 119 absorbs the axial forces generated by the pump against the pump housing.

As shown in FIGURES 1, 5, and 6, a pair of high speed flumes 121 are located within the hull 10, each flume being defined by a vertical wall 123, a lateral wall 125 and a substantially curved wall section 127. Each of the flumes 121 further opens downwardly between an outboard planing surface 13 and the center planing surface 15 and extends from the forward planing surface 11 to the rearward end of the vehicle. Thus, during movement of the vehicle, water enters the forward portion of each of the flumes 121, travels rearwardly therethrough and is discharged out of the rearward end of the vehicle.

A pair of passageways 129 is also located within the hull 10 to provide communication between the flumes 121 and the secondary inlet ports 59. As shown in FIGURES l and 6, each passageway 129 is defined by the lateral walls 131 and 133, and a curved sidewall 135, with each passageway 129 opening into one of the flumes 121. Thus, during movement of the vehicle, a portion of the water entering the high speed flumes 121 also enters into the passageways 129 to communicate with the secondary inlet ports 59.

In operation, when the marine vehicle is in clear water, the valve 61 is in the first position shown in FIGURE 2. This provides the intake of the pump 19 with communication to the primary inlet port 45 and permits the water to enter therethrough. The grill 47 permits the entrance of water into the primary inlet port 45, but prevents any floating or submerged objects from entering the inlet port 45 and damaging the pump components. This arrangement provides the most eflicient ducting means for the propulsion system in clear water, giving the craft a high speed dash capability as well as an eflicient cruise speed.

Upon entering weed-infested waters, the valve 61 is turned to the second position shown in FIGURE 2. This is done by activating the actuator 67, rotating the valve to the new position. The intake to the pump is thereby placed in communication with the secondary inlet ports 59. In this arrangement, water is channelled around the center planing surface 15, into the high speed flumes 121. A portion of the water negotiates a 90 degree turn in entering the converging passageways 129 and the secondary inlet ports 59, while the remaining portion of the water exits through the high speed fiumes 121 past the pump housing and clear of the vehicle. This abrupt change in the direction of flow of the water entering the passageways 129 causes most of the weeds to separate from that portion of the water entering the passageways 129 and be carried by the water flowing through the high speed fiumes 121, thereby minimizing the quantity of weeds being carried into the secondary inlets 33. The small portion of weeds ingested into the pump are then severed into small bits and pieces by the weed cutting device 77 to permit Weed ingestion without damage to the pump components. This permits the pump to operate efficiently without being clogged or damaged by weeds. Finally, being of a shallow draft design with both primary and secondary inlets being well protected, this craft is not susceptible to damage by submerged objects. Therefore, this invention provides a marine vehicle capable of operating efficiently in clear or weed-infested waters.

It will be understood that various changes in designs, materials, steps and arrangements of parts which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention.

We claim:

1. In combination with a marine vehicle having a hull with a bottom planing surface, a water jet propulsion apparatus comprising:

a pump mounted in said hull, said pump having an intake port and a discharge port;

primary inlet duct means having one end connected to said intake port with the other end extending through said hull and said bottom planing surface, thereby defining a primary inlet port;

secondary inlet duct means having one end adapted to communicate with said intake port, with the other end defining a secondary inlet port transversely oriented with respect to said bottom planing surface; and

a passageway defined by wall sections in said hull being in communication with the secondary inlet port.

2. The invention in accordance with claim 1 further including weed chopping means mounted on said secondary inlet port.

3. The invention in accordance with claim 2 wherein the weed chopping means includes:

stator blade means positioned across said secondary inlet port; and

rotary blade means for shearing any weeds ingested into said secondary inlet. i

4. The invention in accordance with claim 1 further including a grill mounted on said primary inlet port.

5. The invention in accordance with claim 4 wherein the grill includes a plurality of arms extending over said primary inlet port.

6. The invention in accordance with claim 1 further including valve means located between said primary and secondary inlet duct means having a first position for providing the pump intake port communication with the primary inlet port while closing communication with the secondary inlet port, and the second position for providing the pump intake port communication with the secondary inlet port while closing communication with the primary inlet port.

7. The invention in accordance with claim 1 further including a high speed fiume defined by wall sections in said hull having an elongated opening through said port planing surface, said fiume communicating with said passageway to divert a portion of the water entering said fiume into said passageway.

8. The invention in accordance with claim 7 wherein said fiume is positioned forward of the secondary pump inlet and extends rearwardly beyond said secondary inlet port.

9. The invention in accordance with claim 8 wherein the water jet propulsion apparatus further includes a second passageway defined by Wall sections in said hull and being in communication with said secondary inlet port; and a second high speed fiume defined by wall sections in said hull having an elongated opening through said bottom planing surface, said second fiume being in communication with said second passageway to divert a portion of the water entering said second flume into said second passageway.

10. The invention in accordance with claim 9 wherein said openings of said fiumes are on opposite sides of said secondary inlet port.

References Cited UNITED STATES PATENTS TRYGVE M. BLIX, Primary Examiner.

US. Cl. X.R. .5 

